Furnace structure



June 24, 1958 R. J. PENROSE 2,840,363

FURNACE STRUCTURE Filed Feb. 14,1956 s Sheets-Sheet 1 Re yno/Q" d. Pennas e INVENTOR.

June 24, 1958 R. J. PENROSE FURNACE STRUCTURE Filed Feb. 14, 1956 v 3Sheets-Sheet 2 Reyna/d d. Pen "0s e INVENTOR June 24, 195 8 F Filed Feb.'14, 1956 R. u. PENROSE 2,840,363

mama: STRUCTURE 3 Sheets-Sheet 3 Reyna/d d. Penroae INVENTOR.

United States Patent Ofiice 2,840,363 Patented June 24, 1958 2,840,363 7FURNACE STRUCTURE I Reynold J. Penrose, Houston, Tex.

Application February 14, 1956, Serial No. 565,509 3'Claims. Cl. 263-21)The present invention relates to a furnace structure and, moreparticularly, relates -to furnace structures of the refractory retort,mufile and hearth type.

As heretofore practiced and well known in the art, all refractory orceramic retort, mufile or hearth type furnaces which introduce a feed ofores, metals or metal objects into a receiving end and pass the feedthrough a furnace and discharge the heat treated feed beyond the wallsof the furnace employ some means of supporting the refractory retort,muflie or hearth in the furnace combustion chamber. These supportingmeans include heat resistant steels, alloys of metals or iron in theconstruction of the support. It is well known that such supports withinthe furnace and in the heat treating zones are subject to warpage byheat expansion and damage caused by the high temperatures of which thistype of furnace is required to operate. This causes considerabledifliculty due to the resultant misalignment of the retort, mufile orhearth I,

'It is also known in the art of heat treating that steels, alloys ofmetalor iron have a tendency to become, according to the composition ofthe metal, what is known as tacky when subjected to temperaturesbeginning as lows as 900 F. That in the heat treatment of certainmaterials, for example, micaceous minerals and/or hydrous silicateminerals for the purpose of expanding them, that these minerals adhereto and form glassy and slaglike fusions to the steels, alloys of metalsor iron that have been used for the construction of retorts, niuflles orhearths, and therefore, free passage is denied and the furnace becomesinoperative. 7

It is therefor a major object of the present invention to provide afurnace structure in which misalignment of refractory retorts, mufllesor hearths caused by the expansion of steels, alloys of metals or ironfor supporting the same within the combustion chamber of the furnace issubstantially eliminated. p

A still further object of the present invention is the provision of afurnace structure including a retort, muffle or hearthin which macaceousminerals and/ or hydrous silicate minerals may be expanded or othermaterials heat treated in the range covering 900 to 2,600 F. withoutbecoming tacky and adhering to and forming glassy and slag-like fusionsto the passageway therein so that a free passage is maintained at alltimes.

A furtherobject of the present invention is the provision of a furnacestructure including a refractory retort, mufile or hearth which isfreely maintained within the heat zone of the furnace structure by meansof compressive forceagainst ends of the former and where said means areso constructed and arranged as to be outside the walls of the furnacestructure and have no metal part within or connected thereto.

Yet a still further object of the present invention is the provision ofa furnace structure havinga novel con struction to prevent thetransmission of heat through the projecting ends of the refractoryretort, muflle or hearth,

the latter being arranged to pass through the furnace walls and projecttherebeyond for receiving material to be heat treated at one end anddischarging the heat treated material at the other end thereof.

Yet a still further object of the present invention is the provision ina furnace structure of a simple but highly eflicient burner for thecombustion chamber thereof for providing luminescent heat from gaseousor oil fuels whereby the heat is evenly distributed over the bottom,sides and top of the material passageway extending therethrough and inwhich the burner is economically and readily constructed out ofconventional material as part of the furnace structure.

It is yet a still further object of the invention to provide a burnerwhich is efiiciently reliable in use and is so constructed and arrangedas to conserve heat and eliminate the use of large amounts of air tokeep the burner cool at operating temperatures.

Other and further objects, advantages and features will be apparent fromthe following description of a presently preferred example of theinvention, given for the purpose of disclosure, and taken in conjunctionwith the accompanying drawings, where like character references desigatelike parts throughout the several views and where V Figure 1 is afragmentary view, in elevation, illustrating means for holding arefractory retort, mufile or hearth in place in the furnace structure,

Figure 2 is a longitudinal elevation, similar to Figure 1, butillustrates in section the means for holding the refractory retort,mufile or hearth in placeand its relation to the furnace structure andburner arrangement,"

Figure 3 is a horizontal, sectional view taken along the line 33 vofFigure 2,

Figure 4 is an end, elevational view taken transversely of the dischargeend as indicated by the line 4-4 of Figure 2, a

Figure 5 is a vertical sectional view taken transversely of the furnacearrangement along the line 55 of Figure 2,

Figure 6 .is a horizontal sectional view of a burner block according tothe invention taken along the line 6 ,6 of Figure 2,

Figure 7 is a horizontal sectional view of the furnace top taken alongthe line 77 of Figure 2, and

Figure 8 is a fragmentary, enlarged side view, in full thickness,illustrating space voids between the central and end sections of theconveyor of the furnace structure.

Referring now to the drawings, and particularly to Figure l, a cradle orsupport arrangement is illustrated for the refractory or ceramic retort,muffle or hearth within the hollow of a furnace. To this end, a suitablemetal I-beam 17, or other similar supporting member, is, provided in agenerally horizontal position to which is attached-at its upper surface,two web-like metal uprights 14 and 14a. The upright 14 may be welded orotherwise rigidly secured, such as bolting, to the I-beam 17. Theupright 14a is attached to the I-beam 17 in any preferred manner topermit longitudinal adjustment along the surface thereof, for example bythe bolts 15, which slidably fit in slots, not shown, in the surfacethereof so that it may adjustably be bolted into position by the bolts15 and the thrust screws 16 to provide endwise compression forsupporting a retort, muffle or hearth,

.as will presently be described.-

is to support the muflle, retort or hearth, as previously mentioned, andto support it by providing endwise or compressive pressure against theouter ends thereof. Prefa p i 3 erably, the material supporting means 14and 14a may take the form of steel or metal blocks, generally ofL-sh-aped configuration, into which the ends and 12 of the retort,muffie or hearth interfit so that endwise or compressivepressure may bebrought to hear thereagainst.

Referring still to Figure 1, the refractory retort, mufile or hearthincludes the refractory or ceramic tile 10 which is placed against thematerial, supporting element 14", as previously described, and therefractory or ceramic tile 12 which is likewise. placed against thematerial supporting element 14a. The'center section .11 is a separaterefractory or ceramic tile'fromthat of the elements 10 and 12 andissupported in position by means of endwise pressure exerted against theelements 10 and 12. Preferably, the interfitting portions 13 and 13,such as a conventional tongue'and groove construction, are provided. on.each end pf thecenter tile 11 and the inner projecting ends of the tiles10 and 12 to assure support of the center section 11. As best seen inFigure 8, the spacevoids 13a are provided at each end of theinterfitting portions 13 and 13' (only one end portion being shown inFigure 8) to provide heat barriers against transmission of heat to theoutside of the furnace chamber. Preferably, this is accomplished byutilizing a somewhat granular ceramic tile 10 although it may beaccomplished in other ways. a a

It is therefore apparent that by adjusting the bolts and 16 the centersection 11 is, supported solely by endwise pressureoccasioned by movingthe upright web 14a towardthe .web. 14, and the related structurepreviously described, and by securing the bolts 15 and thrust screw 16in adjusted position Also, it seems apparent that the retort, mutfle orhearth issupported in. this position freely of the furnace structureproper but is supported. wholly by. means of the cradle arrangementdescribed. It is noted. that a passageway for the fiowof material to beheat treated is thus provided through thecombustion chamber and issupported at its ends free of the combustion chamber. Sincdthepassageway may be of the retort, muffie or hearth type, for convenienceof reference, these and others are all generally designated as apassageway for the material to beheat treated.

Vibrating motion is imparted to the cradle and thereby to the passagewaycomposed of the elements 10, 11 and 12 by means of any conventionalvibrating unit, for example t-heunit illustrated diagrammatically inFigures 1 and 2 and designated bythe reference numeral 20. The

intensity of the vibration is controlled by the means di'agrammaticallyillustrated at 22.

vided with the vibrating unit and the latter is linked to the cradle byany suitablelinking means, such as illustrated in Figures 1 and 2. Nodetailed description is deemed necessary of the vibrating elements asthese are conventional, may be purchased on the market, and as such,form as partof the invention. Obviously, a wide variety of vibratingmeans may be used.

Thecradlc 17 is further supported at the end remote from thevibratingunit 20 by means of the transverse support beam 18 which is supported bythe pair of spring legs 19, as best seen in Figure 4. Thus, due tothespring arrangement, vibrating motion is imparted to the cradle and henceto the retort, muffle or hearth. It is noted that the cradle unit and;passageway are separate from the furnace proper and that no vibratingmotion is imparted to the furnace proper.

i Turning now to Figure 2, the furnace proper is illustrated in positionwith respect to the cradle and passageway for the material to be heattreated. The furnace proper'is illustrated in longitudinal section andincludes the furnace bottom 23 which has the fuel entrance manifold port.24 for furnishing premix fuel to the distributing manifolds 25 andthence to theslots 26, ,asebest seen in Figure 6, into the furnacechamber. directly under the The spring 21 is pro center portion 11 ofthe passageway for the material to be heat treated. For the purpose ofdisclosure and ease of illustration, the furnace top 28, ends 34, 34',36 and 36', and walls 27, see Figures 4 and 5, are shown as large castblocks. In actual practice, these elements may be of any conventionalfurnace construction. The bottom front block 34 is constructed ofsuflicient height to bring its top surface sutficiently close to thebottom of the tile 10 so as to provide a minimum space for the escape ofcombustion products and to provide a minimum clearance for the vibratoryaction of the tile 10. The furnace chamber side of the. block 34preferably should be directly under and vertical to the interfittingportions 13 of the tile 10 and the center tile .11. Similarly, thebottom back block 34 should be similarly arranged, as illustrated.

The top front block 36 fills the space between the top of the sidewallsof the tile 10 and the bottom of the furnace roof that is junctured withthe walls. The furnace chamber side of the block 36 preferably isdirectly above and vertical to the interfitting arrangement 13 of thetile 10 and the center tile 11. The top back block 36 is similarlyarranged with respect to the tile 12.

With the blocks 34, 34 and 36, 36' being so arranged, the space on eachside of the tile 10 and the tile 12 is filled by the blocks 35 and 35 asillustrated in Figures 4 and 5. The position and arrangement of the sideblocks 27 are illustrated in Figures 3, 4 and 5.

The roof of the furnace is diagrammatically illustrated as the block 28in which vent holes 29 are cast or drilled to provide escape for theheat scavenged products of combustion from the furnace, all as best seenin Figures 2 and 7..

The furnace proper is supported by the diagrammatically illustratedblocks 38, ordinarly brickwork, and thus-supports the burner blocks '23and the attached furnace constmction.

In connection with the construction of the furnace proper, and asmentioned previously it should be noted that one of the prime requisitesis the conservation of heat, it being wellknown in the art that the useof gas or oil fired burners require enormous amounts of air, which inturn is used to keep the burner cooled by the passage of air through andaround the burner. This provides large amounts of excess air beyond thatrequired for combustion purposes thereby creating the necessity ofproviding for discharge of the elementsof combustion and excess airwhich carries heat energy into the free air before it can be absorbed bythe material being treated.

It would-therefore be highly advantageous -to provide a burner which didnot require cooling by the air supplied for combustion, but couldoperate at the same temperature as that required within the combustionchamber. Thus, only enough heat units need be supplied to the 'materialbeing treated as would be absorbed by it. The

furnace. structure proper of the present development advantageously doesnot require cooling by the air supplied for the combustion, but operatesat the same temperature required within the combustion chamber. This isaccomplished by providing the burner by casting a block of .perlite andrefractory cement in proportion necessary to provide the requiredstrength and firmness. In casting perlite and cement there is a tendencyof the coarse and fine particles of perlite to. segregate thus making acasting of nonuniform particle distribution. Unexpectedly, by adding upto about 10% by volume of the total mix of a finely pulverized adhesiveor sticky type clay, for example, bentonite, and stirring the mix dry,the clay coats the particles of perlite and cement. Upon the addition ofwater, the clay becomes sticky and causes the cement to adhere to theperlite and thereby produces a uniform casting. Of course, any preferredclay having the desired properties may be used. i

The burner includes the entrance manifold 24 and the interconnecteddistributing manifolds 25 and slots 26 which open into the furnacechamber directly under the furnace are directed upwardly toward thebottomof the center section 11 of the material passageway. Thus, whenfuel sufliciently premixed for combustion is supplied to these openingsand ignited within the furnace, the temperatures required were obtainedandjonly a minimum amount of fuel is necessary as required by absonptionofthe material being treated. The top of the burner block 23 andopenings 26 assume the same temperature of the combustion chamber, butheat transmission into the burner block is not permitted due to theinsulationof the perlite in the casting.- The scavenged products ofcombustions, of course, escape through the openings 29 in the top 28 ofthe furnace.

It is also noted in the furnace structure proper, that a space isprovided between the flat front and back tiles and the center sectionthereof which advantageously provides an effecting barrier against thetransmission of heat to the outside tiles from the center section whichoperates within the furnace at high temperatures. a

Any conventional feeding means may be utilized to feed material to beheat treated to the device, and referring to Figure 2, a supply of ores,objects or minerals are fed from a hopper 31 into the vibrating feederpan 30 which regulates the rate of feed delivered to the tile element ofthe passageway through-the furnace. A conventional vibrating device 32is diagrammatically illustrated and the intensity of the vibratingdevice 32 is controlled by the regulator 33 which thereby controls therate of flow of feed to the passageway. Since the vibrating device andits control elements are all old and well known in the art, no detaileddescription thereof is deemed appropriate or necessary, as previouslymentioned.

Thus, particulate material is delivered by the feeder pan 30 to therefractory tile element 10. By means of the vibrations imparted to itfrom the vibrator 20, as previously described, the material passes overthe surface of the refractory tile 10, through the furnace walls, acrossthe interfitting or tongue and groove joint arrangement 13 and into thecentral portion 11 of passageway where it is subjected to the heat fromthe burner arrangement 23, the time of treatment being controlled by theintensity controller 22 which causes the material to travel either slowor fast, as desired. The rate of flow is thus regulated so that properheat treatment is provided to the material in the central portion 11 ofthe passageway whereupon the material passes over the interfitting jointor tongue and groove arrangement 13 and through the back furnace wallover the surface of the refractory tile element 12 and is thendischarged over the top of the material holdin means 14a into aconventional chute 37 for delivery to a conventional receptacle, notshown. Thus, material is fed to thematerial passageway through thefurnace at a predetermined rate and is passed therethrough at apredetermined rate so that optimum treatment is accorded to the materialbeing heat treated.

In connection with the passageway'through the furnace, it is noted thatit is constructed of' a plurality of parts, namely, the front endsection 10 receiving the feed, which should be long enough to beginbeyond the front of the front furnace wall 34 for the purpose ofreceiving the feed from the vibrating feed pan 30 and .extend throughthe furnace wall to the center section 11 operating within the furnace,the center section being substantially equal in length to the insidelength of the furnace where it joins to the third section whichpreferably is long enough to extend through the back furnace wall 34'and beyond far enough to discharge the feed into a suitable receptacle.

As best seen in Figure 3, the front end section 10 preferably is arefractory tile having walls along two sides and its outer end for thepurpose of retaining the feed upon the surface of the tile. Preferably,the shape of the center section is determined by the product which willbe treated. In most cases a wall is required on two sides to retain theproducts upon the top surface. ,In the event it is necessary to retainexpansive material or a controlled atmosphere is required, it iscontemplated that a roof would be included. Provisions for retaining therequired atmosphere within the retort, muflie or hearth are within theskill of any one practicing the art and, accordingly, no detaileddescription thereof is deemed necessary. It is noted that the end ordischarge tile 12 may have two sides, but that the end wall is omittedso that the material may be discharged over the end of the tile.

It is believed from the foregoing description of a presently preferredexample of the invention, that the mode of operation thereof is apparentand need not be repeated. In short, the development comprises theprovision of a passageway, for example, a ceramic mufiie,

retort or hearth, which is maintained in position by endwise compressionby a cradle or other means which is independent of the furnace proper inthat it is not attached thereto, but the cradle or other means is freeto vibrate thereby vibrating the'passageway through a portion of thefurnace. Thus, controlled rates of flow of material through the furnaceand the heating zone is provided.

The present development may be applied to treatment of a wide variety ofmaterials. For example, it may be used for heat treatment of metals,producing quick lime from oyster shells, dead burning gypsum ormagnesite, expanding perlite, expanding vermiculite in either reducingor oxidizing atmosphere, as desired, in drying crushed ore andconcentrates, for destructive distillation, j in the production of cedaroil or rice oil from rice hulls,

for the complete distillation of oil shale from crude, as well as manyother uses which will suggest themselves to those skilled in the art.The present development advantageously has a very high capacity and accordingly;

eliminates the use of certain auxiliary equipment. For example, indrying crushed ores and concentrates, the high capacity eliminates theuse of rotary kilns and dust collecting equipment.

The present development may be either of the stationary or portabletype.

From the foregoing description it is obvious that the presentdevelopment accomplishes the objects and has the advantages mentioned aswell as others inherent therein.

While only a presently preferred example of the invention has been givenfor the purpose of disclosure, it is obvious that changes in details andconstruction and arrangement of parts may be made which are encompassedwithin the spirit of the invention and the scope of the appended claims.

What is claimed is:

l. A furnace for heat treatment of materials comprising, a furnacechamber provided with oppositely-disposed side walls, said side wallshaving openings therein, a refractory conveyor extending freely throughsaid openings and through said furnace chamber, said refractory conveyorincluding a central section extending through said furnace chamber frompoints adjacent inner sides of said side walls and including endsections projecting from each end of said central section completelythrough said openings, interfitting portions on each said end of saidcentral section and its engaging end of each of said end sections, saidinterfitting portions provided with space voids providing barriersagainst transmission of heat to the outside of the furnace chamber, andmeans independent of the furnace supporting the refractory conveyor inassembled position,,said means including a pair of compression membersdisposed exteriorly of the furnace chamber and engaging the ends of theend sections projecting through the openings and maintaining saidpressive force. a

2-1 A, furnace .for heat treatment of. materials com prising, a furnacechamber provided, with oppositely-dis? posed side walls, said, sidewalls having openings therei arefrictory conveyor extending freelythrough said openings andfthroughsaid furnace chamber, saidrefrictoryconveyor including a central section extending through said furnacechamber and endsections projecting from each end of the central sectioncompletely through said openings, interfittings portionson each end ofsaid central section and on engaging ends of said end sections, andacradle supporting said; conveyorindependently of said furnace chamberand disposed externally thereof, said cradle including a beam extendinggenerally parallel tofsaid" conveyor, apairJofcornpression membersprojecting from said beam andeng'aging outer ends of the end sectionsprojecting through said openings, adjustable means for moving at leastone of said supports towardthe other whereby saidcornpression membersmaintain said refractory conveyor in position by compressive force, andmeans for vibrating said cradle and thereby said conveyor. 1 e

3. A furnace for heat treatment of materials com prising, a furnacechambenprovided with oppositelydisposed side walls, said side wallshaving generally horizontally-aligned openings, therein, a'refractoryconveyor extending freely through said openings and said furnacechamber, said refractory conveyor including a central section extendingthrough said furnace chamber from points adjacent inner sides of saidside walls and including end sections projecting from each end of saidcentral section completely through said openings, interfitting portionson each said end of the central section and its engaging end of each ofsaid end sections, said inter-fitting portions provided with-space voidsproviding barriers against-transmission ofheat, to the outside of thefurnace chamber,.and a cradle supporting said conveyor ifide'plendentlyof said furnace chamber and disposed externally thereof, said, cradleincluding a beam extending generally parallel to said conveyor, a pairof compressiori members projecting from said beam and engaging outerends of the end sections projecting through said openings, at least oneof said compression members adjustably arranged on said beam wherebysaid compressior'i members maintain said conveyor in position bycompressive force, and means for vibrating said cradle and thereby saidconveyor.

References Cited in the file of this patent UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent No. 2,840,363 June 24, 1958 Reynold JPenrose It is herebfi certified that error appears in theprintedspecification of the above -numbered patent requiring correction andthat the said Letters- Patent should read as corrected below.

Column 1, line 38, for "lows" read --low--; line 54, for "macaaceousread --micaceous--; column '7, lines 6 and '7, for "r'efrictory" read refractory--; line 11, for "interfittings" read --interfitting=-; line 27,after "openings' strike out the comma.

Signed and sealed this 7th day of October 1958.

( SEAL) Attest:

KARL H. AXLINE ROBERT C. WATSON Attesting Oflicer Commissioner of Paten

